43DS coolant system problem...

[Amun Ra]

Hello,

I changed the coolant in the Yanmar 4JH3-TE on my 43DS today. Only problem is the calorifier doesn't appear to be warming water anymore. I fear I may have an airlock in that section of the system that runs off the engine to the calorifier.

The engine runs happily with no overheat problems.

I decided to leave it and return in a few days to try again, to see whether running the system up from cold may change anything, and the calorifier produce hot water.

I wonder if anyone has experienced this....and if so how they subsequently solved it!

Best wishes

Julian

[On y va]

Yes, you have an airbubble in your system. If installed correctly, there should be a bleeder nut next or close to your boiler in one of the lines coming from your engine or the return (usually the return). Don´t take the nut off completely, but just open it slowly, so fluid start seeping out (and hopefully some hissing of escaping air). Have a oil soak up cloth under it all. Obviously you have to do this with the engine running. After this check your fluid level in the intercooler (not just the header tank) and fill with the same make/type cooling fluid. Rinse the coolant that may have dripped on wood or in the bilge away with water.

Note: never mix coolants of various types or makes as this causes excessive scaling in your intercooler, which will cause cooling problems when the engine gets older. Also don´t buy the cheap crap from the supermarket (as it was so cheap! ). Get proper Yanmar coolant (or a good other brand). If you have an emergency, better to fill with distilled water or if you don´t have, normal water with a cup of vinegar poored into it.

And it looks like this:


 Attachment Deleted

[Amun Ra]

Thank you very much. I did find a bleed nut close to the calorifier/boiler. I took it off in an effort to try and add coolant. I will do as you suggest next time. Good point about checking the intercooler - I was only checking the header tank and topping up as required.

Great - a plan to try and solve the problem....! Thank you

Best wishes

Julian

[Amun Ra]

Thanks Onyva - I was back on my boat yesterday and did as you suggested. I was surprised by the amount of coolant that was needed to top up the intercooler......and then refilled the overflow bottle. Flashed up the engine, and.....nothing. Tried bleeding as you suggested at the calorifier....and still nothing.

Then decided to run the engine at 2,000rpm and see if that made a difference. It did. Eased the bleed nut again until it weeped...and had piping hot water from the calorifier shortly thereafter.

Another successful job done, thanks to the Board.

Now just need to fix my Jabsco electric loo which won't pull in sea water.....!

[Tafika II]

I notice at the end of your thread you mentioned getting the jabsco toilet to draw in sea water. If you are trying to convert a fresh presurized water system to use sea water instead, it won't work, unless you pressurize the sea water with a pump. Not sure if that's what you are doing.

[Amun Ra]

Tafika,

I serviced my Jabsco electric loo, (37010 series), taking everything apart and replacing the impeller that draws in sea water, the centrifugal impeller that sends out waste and all the seals etc.

Having been working fine beforehand, I now cannot draw sea water in. The system is supposed to be self priming, so I can only assume I have done something wrong somewhere, as the outlet side of the system works brilliantly, far better than before!

I'm sure there are tried and tested techniques for helping the inlet system to prime, just not sure what they are!!

[On y va]

Feb 23, 2014 10:23:07 GMT Amun Ra said:

Thanks Onyva - I was back on my boat yesterday and did as you suggested. I was surprised by the amount of coolant that was needed to top up the intercooler......and then refilled the overflow bottle. Flashed up the engine, and.....nothing. Tried bleeding as you suggested at the calorifier....and still nothing.

Then decided to run the engine at 2,000rpm and see if that made a difference. It did. Eased the bleed nut again until it weeped...and had piping hot water from the calorifier shortly thereafter.

Another successful job done, thanks to the Board.

Now just need to fix my Jabsco electric loo which won't pull in sea water.....!

I did say you had to run the engine. Maybe I should have been more specific that a few revs were needed, to "pump up the volume". I do apologise for not being clear enough.

Marco

[Amun Ra]

Marco...no apology necessary...I would always start running the engine slowly whatever the advice. Much easier to deal with an overheat with low revving engine that miss the alarm at 2,000rpm or more!